The present invention relates to a machine for removing slag and metal remainders from casting ladles or crucibles. The machine includes a frame on which is provided a carriage with a rotating cutter means that is movable in an upwardly inclined direction. Means in association with the frame is provided for tilting a crucible from a lower loading position to an upper working position whereat the axis of the crucible is coaxial with the axis of the rotating cutter means tool.
Casting ladles or crucibles for molten metal will, after being used, have remainders of slag and metal left on their lining of refractory material. Such remainders have to be removed before the ladle can be used again.
Formerly, the ladles were cleaned manually by chipping or by machining with simple air driven machines, but such operation was hard, time consuming and damaging to the health of the workers. Besides, the refractory linings of the ladles often were damaged. The total costs of such manual cleaning were thus high. Later, mechanical devices have been developed, but many of these have not been commercially exploited.
U.S. Pat. Nos. 2,911,662 and 2,963,725, and NO Patent No. 147,940 all show devices for cleaning casting ladles or crucibles and having a movable rotating cutter head. A crucible to be cleaned is placed on a support having a direction of rotation which is opposite to that of the rotating cutter head, and the cutter head is provided in a position eccentric to the axis of the rotation of the crucible. The object with such arrangement is to ensure that all metal and slag remainders are removed from the bottom of the crucible. It is however a major disadvantage of such known devices that the tools are rapidly worn out. This in turn results in that the tools have to be exchanged after a relatively short period of time, e.g. 15-20 cleaned crucibles for each set of tools. Further, it is a disadvantage that such known devices are expensive, due to the fact that two different driving units are used, one for the cutter head and another for rotating of the crucible. Still further, it is a disadvantage with such known devices that they are of a construction having a relatively high height. Particularly, this is the case with the cleaning device according to NO Patent No. 147,940, where the construction height is more than two stories high and where the room in which the device is to be places has to be specially designed.
U.S. Pat. No. 4,153,965 discloses a cleaning device similar to those described above, but which is provided with a "full profile" cutter head and where the crucible is held in a stationary position. By the term "full profile" is meant that the diameter of the cutter head corresponds to the inner diameter of the crucible. The cutter head is provided with three tools or shears spaced peripherally of the cutter head. In addition, the cutter head is provided with a separate cutter unit which has for its object to clean the bottom of the crucible completely. The separate cutter unit is eccentrically disposed relative to the cutter head axis and is driven via a planetary gear. It is a major disadvantage with this known device that it is complicated and mechanically weak in relation to the great strain to which it is exposed during a cleaning operation, and this may well be one of the reasons why it is not commercially exploited. A further disadvantage of such device is the high construction height that is due to the steep inclination angle of the rotating cutter means.